Union members from as far away as Boston were expected to flock to Chicago on Saturday to rally and march in solidarity with teachers as a week-long strike that steamrolled the city inched closer to a resolution.

That the rally comes only a day after a state judge invalidated most of Wisconsin Gov. Scott Walker’s anti-collective bargaining law only served to sweeten the moment for many union members, coming as affirmation that, after decades of decline, unions still have muscle when it comes to showdowns over pay, benefits, and work performance.

Even though it comes before a scheduled vote on Sunday for city teachers to approve what officials are calling the “framework,” the planned rally and march in Chicago on Saturday also highlights the difficulty that US school reformers still face in holding down costs while pushing individual responsibility onto teachers for how their students perform – a main sticking point behind a strike that left 350,000 Chicago students at home for a week. Only 1 in 5 Chicago 8th graders tested as proficient in math and reading in 2011, according to the National Center for Education Statistics, a slight improvement from a decade ago.

After marathon negotiating sessions this week, the teachers union won concessions from the city on pay increases as well as the percentage that teacher evaluations will focus on student test scores. Mayor Rahm Emanuel called it an “honest and principled compromise.”

The city wanted 40 percent of each teacher evaluation to be tied to their students’ test scores, but the agreed-upon number, according to published reports, is likely to be more in the 30-percent range. For their part, teachers worried that the sudden use of test scores as part of the evaluations would unfairly punish some teachers.

The pressure on politicians to rein in the unions is high, even in Democrat-controlled Chicago, where the strike exposed a rift among Democrats about how to rein in school costs while dramatically improving the city’s low test scores and high dropout rate.

So-called “Cadillac” benefit packages negotiated by public unions have been widely blamed for fueling public debt at an unsustainable rate, sparking mayors and governors to debate the future of such benefit packages.

Exacerbating that trend: Poor economic conditions, which have helped stir class resentment as private industry workers with stagnant wages compare their compensation to deals like the one now in front of Chicago teachers: a 16 percent across the board raise over four years.

The philosophical clash was evident in Wisconsin, too, where large-scale protests last year were unable to stop a new law that stripped collective bargaining rights from most public employees, laying the groundwork for Gov. Scott Walker – who also became the first US governor to survive a recall election – to steer the state from a $3 billion shortfall to a slight surplus in the span of a year.

On Friday, a Wisconsin county judge nullified the law, sending Mr. Walker calling for an appeal while unions claimed victory.

"As we have said from day one, Scott Walker's attempt to silence the union men and women of Wisconsin's public sector was an immoral, unjust and illegal power grab," Phil Neuenfeldt, president of the Wisconsin State AFL-CIO, told the Associated Press.

The framework that will be presented to unionized Chicago teachers on Sunday reportedly includes steeper step increases in pay for tenured teachers, and it lays the ultimate fate of the teacher evaluation piece on the findings of a new city-union joint commission while putting some of the new evaluation standards in effect under the contract.

According to Chicago media, the deal would also add an additional annual 2 percent cost-of-living pay raise, while keeping class sizes at current levels.

“Our delegates are not interested in blindly signing off on something they have not seen,” Ms. Lewis said, according to CBS News. “A framework is one thing. We think it’s a framework that can get us to an agreement, but we’re not quite there.”

But despite that caution, some union members flocking to the Chicago rally from Minnesota and other states were using words like “celebration” and “victory” to describe the result of the week-long strike, which was the first for Chicago teachers in 25 years.